[Users] UAC replace_from replace_to

[Greg Fausak]

I need some functions similar to the UAC module's replace_from/ 
restore_from stuff.
Before I get started, is there any reason this can't be done?

I have a provider that insists on seeing an e164 number followed by  
@1.2.3.4 (ip address) in
the from and to headers.  It looks like the replace_from gear will  
handle the from line.  I have
seen references to the to header.  I think they can be interchanged?   
Is it possible that
I can already change the to header and don't know it?

-greg